What first article inspection is
First article inspection (FAI) is the full verification of a part, or an assembly, made with the production tooling, materials, process and people. Every requirement on the drawing is checked: each dimension and tolerance, the material, finish, markings and notes. The result is a first article inspection report (FAIR) showing each requirement, the measured result and whether it conforms.
FAI happens before production is released, and again when something important changes. It answers one question: if the factory keeps doing exactly what it did to make this part, will the parts be right?
Formal FAI and first-piece checks
The term covers two different practices, and suppliers in Asia use both:
- Formal FAI. A full report against every drawing requirement, done for a new part or after a significant change. In aerospace this is defined by AS9102; automotive suppliers use a broader approval package called PPAP. Consumer and industrial hardware programs usually adopt a lighter version of the same principle.
- First-piece inspection. A check of the first unit made after each setup, changeover or shift start, done by in-process quality control. It covers the critical characteristics, not the whole drawing. See IQC, IPQC and OQC.
When a supplier says it “does FAI”, ask which of the two it means.
What an FAI report contains
- A ballooned drawing. Every requirement is numbered on the drawing, so nothing is skipped and each result can be traced.
- A result for each numbered characteristic. Nominal and tolerance, measured value, measuring method or instrument, pass or fail.
- Material evidence. Certificates or test reports for the resin, metal or other material used.
- Special processes. Results or certificates for plating, painting, heat treatment and other processes that cannot be fully verified on the finished part.
- Functional and cosmetic results, where the drawing or specification calls for them.
- Traceability. Part revision, tool and cavity number, production date and lot.
When to repeat FAI
Plan a new FAI, or a partial one covering the affected characteristics, when:
- The design changes in a way that affects form, fit or function (see ECN/ECO)
- Tooling is modified, significantly repaired, replaced or moved
- Production moves to another line, site or subcontractor
- The material or the material supplier changes
- Production restarts after a long pause
How FAI differs from neighboring steps
| Step | What it shows |
|---|---|
| T1 mold trial | The tool can make the part, and what still needs fixing |
| First article inspection | The production process makes a part meeting every drawing requirement |
| Golden sample | The approved reference for appearance and function |
| Cpk study | The process makes conforming parts consistently, not just once |
| AQL lot inspection | A specific lot is acceptable to ship |
FAI proves that a process can make the part right. It does not prove the process will keep doing so; that is the job of capability data and ongoing inspection.
Common mistakes
- Measuring only critical dimensions and calling it an FAI. If a requirement is not on the report, it was not checked.
- One cavity only. In a multi-cavity mold, each cavity is effectively its own process. Inspect parts from every cavity.
- Parts not made on the production process. Parts from a prototype setup, a different machine or with hand finishing do not count.
- A summary without data. A one-page “all pass” sheet cannot be checked. Ask for the measured values.
- No repeat after changes. A tool repair or a material switch quietly invalidates the old report.
Where Zefinity helps
A first article report exposes gaps on both sides: requirements the factory has no way to measure, and requirements the drawing leaves open to interpretation. Within manufacturing engineering support and QA follow-up, Zefinity helps teams define what a first article report must include, reviews the data suppliers submit, and tracks open items so they are closed before production is released rather than after.
Frequently asked questions
Who performs first article inspection, the supplier or the buyer?
Usually the supplier performs it and submits the report, and the buyer reviews and approves it. Buyers often re-measure some characteristics themselves or through a third party, particularly critical dimensions. Record the approval, because production release depends on it and later changes are judged against it.
How many parts are measured in an FAI?
A formal FAI is often done on one part per cavity or per production stream, with every characteristic measured. Some programs ask for several parts to see early variation. A handful of parts is still not a capability study; that needs many more measurements, taken across normal production runs.